@article{scholars13342,
         journal = {Journal of Cleaner Production},
            year = {2020},
       publisher = {Elsevier Ltd},
            note = {cited By 24},
           title = {Ethylene production from ethanol dehydration over mesoporous SBA-15 catalyst derived from palm oil clinker waste},
          volume = {249},
             doi = {10.1016/j.jclepro.2019.119323},
             url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075870648&doi=10.1016\%2fj.jclepro.2019.119323&partnerID=40&md5=fe2c738b5e12bb07547d0c898180a6ee},
            issn = {09596526},
        abstract = {The silica-rich palm oil clinker (POC) from oil palm agroindustry is often dumped in landfill. This work investigated the valorisation of POC into Santa Barbara Amorphous-15 (SBA-15) catalyst, the modulation of its surface acidity, and its application in dehydration of ethanol to ethylene. With commercial SBA-15 SBA-15(Comm.) as reference, the successful fabrication of POC-derived SBA-15 POC-SBA-15(pH = 3, 5, and 7) were validated by spectroscopic and microscopic characterisation. From the results of temperature-programmed desorption of ammonia, the SBA-15(Comm.) have high strong acidity while POC-SBA-15 exhibit enriched weak-moderate acidity. For ethanol dehydration over SBA-15 at 200{\^a}??400 {\^A}oC, the ethanol conversion (XC2H5OH) and ethylene selectivity (SC2H4) rise with temperature. The catalytic activity was ranked as SBA-15(Comm.) \< POC-SBA-15(3) \< POC-SBA-15(7) \< POC-SBA-15(5). Spent catalysts characterisation unanimously confirms the least carbon deposition on POC-SBA-15(5), which subsequently used to study the effect of initial ethanol concentration and liquid hourly space velocity (LHSV). When 99.5 wt\% ethanol diluted to 50 wt\%, the competitive adsorption between ethanol and water reduces XC2H5OH but enhances SC2H4. Further ethanol dilution ({\^a}??30 wt\%) deteriorates SC2H4 following remarkable ethanol steam reforming at elevated temperature ({\^a}?Y350 {\^A}oC). For 50 wt\% ethanol dehydration over POC-SBA-15(5) at 400 {\^A}oC, a greater LHSV furnishes a higher ethanol partial pressure that increases XC2H5OH but decreases SC2H4. When LHSV \>16 mL/g{\^A}.h, the saturation of finite active sites with adsorbates renders the drastic declination of XC2H5OH and SC2H4. For ethanol dehydration over POC-SBA-15(5), the optimal conditions are temperature of 400 {\^A}oC, initial ethanol concentration of 50 wt\%, and LHSV of 16 mL/g{\^A}.h. Fresh POC-SBA-15(5) steadily catalyses the optimal process (73.33\% XC2H5OH and 84.70\% SC2H4) up to 105 h. Meanwhile, regenerated POC-SBA-15(5) achieves a lower catalytic activity (71.95\% XC2H5OH and 81.96\% SC2H4). {\^A}{\copyright} 2019 Elsevier Ltd},
        keywords = {Ammonia; Catalyst activity; Dehydration; Ethylene; Palm oil; Silica; Steam reforming; Temperature programmed desorption, Ethanol dehydration; Mesoporous SBA-15; Operating condition; Palm oil clinkers; Surface acidity, Ethanol},
          author = {Cheng, Y. W. and Chong, C. C. and Cheng, C. K. and Ng, K. H. and Witoon, T. and Juan, J. C.}
}